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      <a id="pvsbufread2"></a>
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      <a id="Indexpvsbufread2" class="indexterm"></a>
      <div class="refnamediv">
        <h2>
          <span class="refentrytitle">pvsbufread2</span>
        </h2>
        <p>pvsbufread2 — 
      This opcode reads a circular buffer of f-signals (streaming PV signals), with binwise additional delays.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp138121856"></a>
        <h2>Description</h2>
        <p>
      This opcode reads from a circular buffer of length ilen (secs),
      taking a handle for the buffer and a time pointer, which holds the
      current read position (also in seconds). It is used in conjunction with a <span class="emphasis"><em>pvsbuffer</em></span> opocde. 
      Reading is circular, wrapping around at the end of the buffer. Extra delay times are taken from
      a function table, with each point on it defining a delay time in seconds affecting the corresponding bin.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp138123872"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">fsig <span class="command"><strong>pvsbufread2</strong></span>  ktime, khandle, ift1, ift2 </pre>
      </div>
      <div class="refsect1">
        <a id="idp138126000"></a>
        <h2>Initialization</h2>
        <p>
      <span class="emphasis"><em>ift1</em></span> -- function table with at least fftisze/2+1 points where delays (in secs) for bin amplitudes are
      set (function table positions are equivalent to bin numbers)
    </p>
        <p>
      <span class="emphasis"><em>ift2</em></span> -- function table with at least fftisze/2+1 points where delays (in secs) for bin frequencies are
      set (function table positions are equivalent to bin numbers)
    </p>
      </div>
      <div class="refsect1">
        <a id="idp138128784"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>fsig</em></span> -- output pv stream
    </p>
        <p>
      <span class="emphasis"><em>ktime</em></span> -- time position of reading pointer (in secs).
    </p>
        <p>
      <span class="emphasis"><em>khandle</em></span> -- handle identifying the buffer to be read. When using k-rate
      handles, it is important to initialise the k-rate variable to a given existing handle. When changing
      buffers, fsig buffers need to be compatible (same fsig format).
    </p>
        <p>
      With this opcode and <a class="link" href="pvsbuffer.html" title="pvsbuffer"><em class="citetitle">pvsbuffer</em></a>, it is possible to, among other things:
      </p>
        <div class="itemizedlist">
          <ul class="itemizedlist" style="list-style-type: disc; ">
            <li class="listitem">time-stretch/compress a fsig stream, by reading it at
        different rates</li>
            <li class="listitem">delay a fsig or portions of it.</li>
            <li class="listitem">'brassage' two or more fsigs by switching buffers, since
        the reading handles are k-rate. Note that, when using k-rate
        handles, it is important to initialise the k-rate variable to a
        given handle (so that the fsig initialisation can take place)
        and it is only possible to switch handles between compatible
        fsig buffers (with the same fftsize and overlap).</li>
          </ul>
        </div>
        <p>
    </p>
        <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
          <table border="0" summary="Note">
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              <td rowspan="2" align="center" valign="top" width="25">
                <img alt="[Note]" src="images/note.png" />
              </td>
              <th align="left">Note</th>
            </tr>
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              <td align="left" valign="top">
                <p>
        It is important that the handle value passed to <span class="emphasis"><em>pvsbufread2</em></span> is valid and was created by <a class="link" href="pvsbuffer.html" title="pvsbuffer"><em class="citetitle">pvsbuffer</em></a>. Csound will crash with invalid handles.
      </p>
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      <div class="refsect1">
        <a id="idp138138560"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the pvsbufread2 opcode. It uses the file <a class="ulink" href="examples/pvsbufread2.csd" target="_top"><em class="citetitle">pvsbufread2.csd</em></a>.
      </p>
        <div class="example">
          <a id="idp138140432"></a>
          <p class="title">
            <strong>Example 679. Example of the pvsbufread2 opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>

<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>
<span class="ohdr">ksmps</span>  <span class="op">=</span> 64
<span class="ohdr">0dbfs</span>  <span class="op">=</span> 1
<span class="ohdr">nchnls</span> <span class="op">=</span> 2

<span class="oblock">instr</span> 1
kcnt     <span class="opc">init</span>         0
ifftsize <span class="op">=</span>            2048
ihop     <span class="op">=</span>            ifftsize<span class="op">/</span>4

a1       <span class="opc">diskin2</span>      "beats.wav", 1, 0, 1
a1       <span class="op">=</span>            a1<span class="op">*</span>0.5
fsig1    <span class="opc">pvsanal</span>      a1, ifftsize, ihop, ifftsize, 1
ih, kt   <span class="opc">pvsbuffer</span>    fsig1, 10

fsig2    <span class="opc">pvsbufread2</span>  kt, ih, 1, 1
fsig3    <span class="opc">pvsbufread2</span>  kt, ih, 2, 2

a2       <span class="opc">pvsynth</span>      fsig3
a3       <span class="opc">pvsynth</span>      fsig2

         <span class="opc">outs</span>         a2, a3
<span class="oblock">endin</span>
<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
<span class="stamnt">f</span>1 0 2048 -7 0 128 1.1 128 0.5  256 1.8 512 1.1 1024 0.1
<span class="stamnt">f</span>2 0 2048 -7 1 128 0.2 128 0.05 256 0.5 512 0.9 1024 0.1

<span class="stamnt">i</span>1 0 60
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
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        <p><br class="example-break" />
    </p>
      </div>
      <div class="refsect1">
        <a id="idp138144720"></a>
        <h2>See Also</h2>
        <p>
      <a class="link" href="pvsanal.html" title="pvsanal"><em class="citetitle">pvsanal</em></a>,
      <a class="link" href="pvsynth.html" title="pvsynth"><em class="citetitle">pvsynth</em></a>,
      <a class="link" href="pvsbuffer.html" title="pvsbuffer"><em class="citetitle">pvsbuffer</em></a>,
      <a class="link" href="pvsadsyn.html" title="pvsadsyn"><em class="citetitle">pvsadsyn</em></a>
    </p>
      </div>
      <div class="refsect1">
        <a id="idp138149648"></a>
        <h2>Credits</h2>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: Victor Lazzarini</td>
          </tr>
          <tr>
            <td>July 2011</td>
          </tr>
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    </p>
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